1. Field of the Invention
The invention relates to dishwashers. In one aspect, the invention relates to a dishwasher with a bulk wash aid dispenser. In another aspect, the invention relates to a bulk wash aid dispenser for use in a dishwasher.
2. Description of the Related Art
Most automated household dishwashers for cleaning utensils, such as dishes, plates, bowls, glassware, pots and pans, and silverware, have a dispenser for storing and releasing a single or individual charge of one or more wash aids, such as detergents, rinse aids, and film removers, at appropriate times during a dishwashing cycle. Typically, the volume of an individual charge of a wash aid is released all at once into the wash chamber. Because the dispenser holds only a single charge of each wash aid, the user must provide new individual charges of the wash aids at the beginning of each dishwashing cycle. This procedure is inconvenient for the user who must remember to supply the wash aids and spend time refilling the appropriate dispensers. Furthermore, the amount of wash aid introduced into the dispensers is dependent on the user. Although the dispenser can have fill level indicators, users can ignore the recommendations and use either too much or too little wash aid. Improper quantities of wash aid can deposit residue and films or inadequately clean the utensils.
The single-charge dispensers also prevent the use of more complex dishwashing cycles, which can provide for better overall cleaning. For example, depending on the soil load on the utensils, it can be beneficial to release a portion of the single charge at different times during the dishwashing cycle, rather than releasing all of the single charge at the same time. Similarly, it can be beneficial to have dishwashing cycles with multiple wash cycles interspersed with multiple rinse cycles. Each of the wash and rinse cycles could use different amounts of wash aid. The amounts of wash aid could be more than or less than a single charge, and the wash aid could be dispensed all at once or in portions of the total wash aid. Single charge dispensers cannot effect these more complex dishwashing cycles.
The problems associated with single-use wash aids in dishwashers are remedied by bulk wash aids. In general, a bulk wash aid is a solid or liquid agglomeration of multiple charges of a wash aid for use in multiple dishwashing cycles. When this form of wash aid is employed, the user does not have to replace it between each use of the dishwasher nor determine the quantity of wash aid in the dishwasher liquid solution. Rather, a bulk wash aid dispenser meters the amount of wash aid supplied to the solution.
Some household dishwashers have bulk wash aid dispensers that continuously expose the bulk wash aid supply to the recirculating liquid in the dishwasher. Because the bulk wash aid is constantly in fluid communication with the liquid, it is difficult to properly meter an accurate charge of detergent. Additionally, dishwashers can utilize a rinse cycle wherein no wash aid is desired, but dishwashers with such bulk wash aid dispensers are not able to cease the release of wash aid into the rinse liquid. Furthermore, some bulk wash aid dispensers can only accommodate solid bulk wash aids; however, it is often desirable to utilize both solid and liquid wash aids during a dishwashing cycle.